Exhaust silencer



Patented July 16, 1929- WILLIAM HENRY GRAHAM FUItNIVALL,

nAvInjBE RTHA MCLAREN; ND D AR .moon LASCHINGERj'QF'JOHANNESBURG,rnANs'vAAL, sourrr AFRICA;

EXHAUST sinnivcnn.

Application filed April 13, 1928, Serial No.

The present invention refers to exhaust silencers of the kind comprisinga container partially filled with a loose mass of balls. At the base ofthe container is a perforated partition, through which the exhaust gasesare conducted into the container; and the balls are of such size thatthey are lifted and agitated by the gases. Thereby they deprive thegases of their noise producing energy or so modify such energy as toreduce the noise;

whilst the agitation of the balls prevents accumulation of carbon andother solid deposits in the silencer.

The purpose of the invention is to provide a silencer of this kind whichminimizes back pressure in the engine.

The invention is illustrated in the accompanying drawing in which Fig. Iis a longitudinal vertical section of a silencer and Fig. II is a plan.

The ball container comprises a member 2 with vertical walls, aperforated base plate 3 clamped between the members 2 and 4, and a Wiremesh screen 5 similarly clamped between members 2 and 6. A loose mass ofballs 7 partially fills the ball container; and, when dormant, rests onthe base plate 3. The member 2 is considerably elongated on onehorizontal axis a which in practice is the axis lying fore-and-aft of amotor vehicle on which the silencer is fitted.

The hollow inlet member 4 is split at 8 and provided with bolt lugs 9for clamping it to the end of a horizontal exhaust pipe. It extendsparallel with the axis a and is curved to deliver the exhaust gasesupwardly to the ball container.

The hollow outlet member 6 is bolted to the upper end of the ballcontainer and conducts the gases to the rearwardly directed andflattened orifice 10 of a fish tail 11, extending in the generaldirection of the axis a but oppositely to the member 4.

45 It will be seen that the exhaust gases flow first horizontally, thenupwardly and then again horizontally, but the elongation of the ballchamber in the direction of their horizontal flow enables thechanges ofdirection to be made in easy curves; this being a factor in minimizingthe back pressure.

The wire screen 5 has the usual rectangular mesh preferably with oblongopenings, so that 269,819, and in Germany August 26, 1926.

and their diameter and distance are'so proportioned to the diameter ofthe balls that it is possible for the balls to settleinto all orsubstantially all of the holes. Balls of inch in diameter have beenfound suitable for a motor car exhaust silencer. Wit-h balls of thissize the provision of holes of inch diameter and spaced inch apartenables all or practically all the holes to be occupied by the lowermostlayer of a mass of balls settling by gravity.

The successive opening of the engine exhaust valves tends to cause thegases to pass through the exhaust system in a series of waves ofpressure alternating with waves of rarefaction. The point at which thegases are discharged from the silencer into the atmosphere acts as amode from which such waves are reflected back into the exhaust system,so interfering with on-coming waves and raising the back pressure in thesystem.

The effect of the construction described is that the balls are raisedand agitated by a wave of pressure and thereby diminish its noise-makingcapacity. When the succeeding wave 0 rarefaction arrives, the ballssettle back onto the plate 3, enter the holes 12 or a substantial numberof said holes and act as non-return valves to prevent the ases or theatmospheric air from flowing ack into the exhaust pipe.

We'cIaim: v

An exhaust silencer comprising two elbowshaped members, the one anexhaust member, having a cylindrical end adapted to be clamped to anexhaust pipe and having an upwardly directed end of oval cross sectionand having a downwardly directed oval shaped end of similar area andcross section to the corresponding end of the inlet member, anintermediate drum of oval cross section secured between the oval ends ofthe inlet and outlet members, upper and lower screens for said drumclam'fizd between said round perforations of ball retaining width.

drumlmd the'hdhoent mem' rs, balls in said In testimony whereof we havesigned our drum "between said screens, the lower screen names to thisspecification. 1 being formed with perforations of such size 5 .aei as:to substantially all 06- I I wkmyiulclude kgy 7 balls, when in stateofo repose,

the upper screen being provided with non- V EDGAR JACOB LASCHINGER.

